What are Rare Earth Elements?
Rare earth elements (REEs) are a group of 17 metals that aren’t actually rare in the Earth’s crust — but are hard to extract and refine. Two of them, neodymium (Nd) and praseodymium (Pr), are essential for the powerful permanent magnets that drive nearly every electric motor in a robot.
Why Robots Need Them
Electric motors work by creating magnetic fields. The strongest magnets are made from an alloy called NdFeB (neodymium-iron-boron). These magnets are:
- 10× stronger than ferrite (cheap) magnets
- Small and light enough for humanoid joints
- Essential for high-Torque, compact actuators
Without NdFeB magnets, humanoid robots would need motors 5–10× larger and heavier. The form factor becomes impractical.
The Supply Chain Reality
| Stage | China Share | Notes |
|---|---|---|
| Mining | 60% | Significant deposits also in Australia, US, Vietnam |
| Refining | 84% | The critical chokepoint. Only China has scaled chemical separation |
| Magnet manufacturing | 92% | Japan (Hitachi, TDK) has some capacity; rest is Chinese |
The Geopolitical Risk
China has used REE export controls as leverage before — notably during a 2010 dispute with Japan. In 2023, China restricted exports of gallium and germanium (chip materials). NdFeB magnets are on the same list of strategically controlled items.
The West is responding:
- MP Materials (US) is restarting a California mine and building a Texas refinery
- Lynas (Australia) ships ore to Malaysia for processing
- European Raw Materials Alliance is funding alternative projects
But no Western refinery operates at Chinese scale today. The timeline to build one is 5–7 years.
Alternatives
- Switched reluctance motors: No magnets needed. Viable for some applications, but less torque-dense
- Ferrite motors: Weaker, heavier. Possible for low-performance robots
- Samarium-cobalt magnets: Strong, but use expensive and strategically significant cobalt
The Bottom Line
Rare earth magnets are the single most geopolitically exposed component in a humanoid robot. vulnerabilities\ is why Tesla, Figure AI, and defense programs are all watching NdFeB supply chains closely.